Mayor de Blasio’s planned presidential forum next month in Iowa was cancelled, the Progressive Agenda Committee announced Tuesday.

Mayor de Blasio’s political group has canceled its presidential forum in Iowa, officials announced Tuesday.

The executive director of the Progressive Agenda Committee, which de Blasio founded, said the Dec. 6 forum was off — after no presidential candidates publicly committed to attend.

The forum came to be widely seen as a political mess for de Blasio, who has been criticized for his focus on national issues and waffled for months on an endorsement of Hillary Clinton — but ultimately lent his backing before waiting to hear her progressive bona fides at the Iowa event.

“It is clear other efforts beyond the previously planned presidential forum will more effectively advance the cause of fighting income inequality,” said Geri Prado, the committee’s executive director. “However, TPAC will continue to work with our leaders at the local, state and federal levels to implement tangible solutions to what is the crisis of our time.”

She said the event is no longer necessary because income inequality has already become a central part of the presidential contest, and said the group would form a new leadership committee in the coming weeks to “implement an aggressive multi-platform communications effort with our supporters to ensure these issues remain part of the national conversation — throughout this election season, and into the future.”

Earlier Tuesday, de Blasio publicly waffled on whether he would even attend his own group’s forum.

“That situation, we’ll have more to say on soon, and the point is, when I see an opportunity to make the changes in these policies, I’m going to obviously take that opportunity,” he said in an interview on NY1.